Lancashire Police has requested the help of a leading investigator from the National Crime Agency (NCA) in its search for Nicola Bulley, it's been claimed.
The force has so far failed to solve the mysterious disappearance of the dog walker, who has now been missing for more than three weeks.
Ms Bulley, 45, hasn't been seen since January 27, after she dropped her two daughters at school.
She was last seen shortly after 9am, when she was walking her springer spaniel Willow on her usual riverside stroll.
The police set out to find Ms Bulley shortly after she was reported missing, but she's yet to be found.
After a series of failed searches, Lancashire Police drafted in one of the UK's top detectives in a bid to finally make a major breakthrough.
The officer led a specialist team from the NCA, which is the agency that usually deals with organised crime, trafficking, and even fraud.
Most recently, the detective worked on the case of murdered police community support officer Julia James, according to The Sunday Times.
Ms James, 53, was killed by Callum Wheeler, 22, after he ambushed her while she walked her dog near to her Kent home.
Wheeler was later handed a life sentence, and was told he'd serve a minimum 37 years in prison.
The top investigator - who hasn't been named - reportedly advised Lancashire Police to bring external experts into the search.
That could include digital media specialist, forensic clinical psychologists, and even a dog behavioural specialist.
Lancashire Police was criticised earlier this week for disclosing personal details about Ms Bulley's "vulnerabilities".
Privacy campaigners raised concerns about the police's release of private details into the public domain.
The force subsequently confirmed it would conduct an internal review into the investigation.
Meanwhile, Ms Bulley's dad, 73-year-old Ernie, said the family was desperate for answers.
The family released an emotional statement earlier this week, appealing directly to the missing mum.
They wrote: "Nikki, we hope you are reading this and know that we love you so much and your girls want a cuddle. We all need you home.
"You can reach out to us, or you can contact MissingPeople.org.uk. Don’t be scared, we all love you so very much."
